JP-10-220272A (U.S. Pat. No. 6,142,121) shows a fuel injection system in which a fuel pump supplies fuel to a fuel injector which injects fuel into a cylinder of an internal combustion engine. This fuel injection system is provided with a fuel pressure sensor. The fuel pressure sensor is arranged in a common-rail to detect fuel pressure supplied to the injector. Each control unit configuring the fuel injection system, such as the fuel pump, a pressure reducing valve and the like, is feedback controlled so that the detected fuel pressure comes close to a target fuel pressure.
According to the inventors' knowledge, a fuel-supply quantity that is actually supplied to the fuel injector is an important parameter to control the fuel injection system with high accuracy. For example, an operation command value of the control unit is computed or corrected based on the fuel-supply quantity, so that each control unit can be accurately controlled.
Although JP-10-220272A describes the feedback control, it is silent about the above inventors' knowledge. That is, JP-10-220272A fails to show a configuration to detect the fuel-supply quantity.